SOIL FUNGI 265 



posing cellulose. It remained for the more recent investigators 98-101 to 

 demonstrate definitely that not only do fungi decompose cellulose, but 

 that pure cultures of fungi will decompose quantitatively within 3 to 

 4 weeks 50 per cent or more of the cellulose added in the form of filter 

 paper. The addition of cellulose to the soil brings about an extensive 

 development of fungi, most of which possess a very strong cellulose 

 decomposing power. These include various species of Penicillium, 

 Aspergillus, Trichoderma, Sporotrichum, Fusarium, and other forms 

 which were found to be able to decompose cellulose. McBeth 102 sug- 

 gested that, in moist soils, particularly in humus soils, the fungi play a 

 much more important part than in dry soils. Daszewska" found 

 Verticillium celhclosae, V. glaucum, Sporotrichum olivaceum and various 

 other Sporotricha, Fusaria, Monosporia, Alternaria and Monilia among 

 the strongest cellulose decomposing fungi in the soil. She also con- 

 cluded that the Hyphomycetes play a much more important part than 

 the bacteria in the decomposition of cellulose in the soil, the color of 

 the humus being due to the color of the mycelium and the spores of 

 fungi. Sugars and alcohols were formed as intermediary products. 



Otto 101 investigated a series of soil fungi and found the following to 

 be able to decompose true celluloses actively: Stemphylium, Mycogone, 

 Strachybotrys, Trichoderma, Cladosporium (Hormodendrum), and 

 certain species of Penicillia. The cellulose was decomposed by the 

 fungi by means of hydrolytic enzymes, which are produced only in the 

 presence of cellulose in the medium. None of the Phycomycetes in- 

 vestigated could decompose cellulose. Further information on cellulose 

 decomposition by fungi is given elsewhere. 103-105 



98 Koning, C. J. Beijdrage tot de kennis van het leven der humicole fungi 

 en van de scheidkundige Processen, welche bijd. humificatie hebben. Verle- 

 sungen v. de gewone Vergad. d. Wis. e. nat. Afdelling. November, 1912. 



99 Daszewska, W. Etude sur la dcsagregation de la cellulose dans la terre de 

 bruyere et la tourbe. Bull. Soc. Bot. Geneve., ser. 8, fas. 8, 255-316. 1913. 



100 McBeth, I. G., and Scales, F. M. The destruction of cellulose by bac- 

 teria and filamentous fungi. U. S. Dept. Agr. Bur. Plant Indus. Bui. 266, 1913; 

 Scales, F. M. Some filamentous fungi tested for cellulose destroying power. 

 Bot. Gaz., 60: 149-153. 1915. 



101 Otto, H. Untersuchungen fiber die Auflosung von Zellulosen und Zell- 

 wanden durch Pilze. Inaug. Diss. Berlin. Borntraeger. 1916. 



102 McBeth, 1916 (p. 197). 



103 Heller, F. Die Zersetzung der Zellulosen durch Pilze. Inaug. Diss. 

 Rostock. 1917. 



104 Hopfe, A. Bacteriologische Untersuchungen tiber die Celluloseverdauung. 

 Centrbl. Bakt. I, 83: 374-386, 531-537. 1919. 



104 Traaen, 1914 (p. 238). 



